Google scientists said on Wednesday that they have reached a major milestone in their quest to develop efficient quantum computing, with a new study showing that they have reduced the rate of errors – which has hampered the technology far more than ever.
Quantum computing was seen as a revolutionary advance that uses our growing scientific understanding of the subatomic world to create a machine with powers far beyond those of today’s conventional computers.
However, the technology is largely theoretical, and there are still many serious problems along the way – including extremely high error rates.
In new research published in the journal natureGoogle’s Quantum AI lab described a system that can significantly reduce the error rate.
That could give the US tech giant a leg up on its rivals such as IBM, which is also working on superconducting quantum processors.
While traditional computers process information in bits that can be represented by 0 or 1, quantum computers use qubits, which can be a combination of both at the same time.
This property, known as superposition, means that a quantum computer can simultaneously compute a huge number of possible outcomes.
The computers take advantage of some of the most fascinating features of quantum mechanics, including a phenomenon called “entanglement”—where two members of a pair of bits can exist in the same state, even if they are far from each other. together.
But a problem called decoherence can cause the qubits to lose their information when they leave their quantum state and come into contact with the outside world.
This vulnerability creates high error rates, which increase with the number of qubits, frustrating scientists who want to scale up their experiments.
However, the Google team said they have demonstrated for the first time in practice that a system using correction code can detect and correct errors without affecting the information.
The system was theorized for the first time in the 1990s, however previous attempts just turned up more errors, not less, said Hartmut Neven from Google, co-author of the study.
“But if all components of your system have low enough error rates, the magic of quantum error correction kicks in,” Neven told a press conference.
Julian Kelly, co-author of another study, called the development “an important scientific milestone”, saying that “quantum error correction is the single most important technology for the future of quantum computing”.
Neven said the result was still “not good enough, we need to achieve a low overall error rate”.
He added that there are “more steps to come” to realize the dream of a usable quantum computer.
Google claimed in 2019 to have achieved a milestone known as “quantum supremacy”, when the tech giant said its Sycamore machine performed a calculation in 200 seconds that would take a traditional supercomputer 10,000 years to complete.
However, the achievement has since been disputed, with Chinese researchers saying last year that a supercomputer could beat the Sycamore time.
Suppressing quantum errors by scaling a surface code logical qubit, nature (2023). DOI: 10.1038/s41586-022-05434-1
Towards error-robust quantum computers, nature (2023). DOI: 10.1038/d41586-022-04532-4
© 2023 AFP
Quote: Google hails ‘milestone’ in quantum computing (2023, February 23) retrieved on February 23, 2023 from https://phys.org/news/2023-02-google-hails-key-milestone-quantum.html
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